So many readers asked about the metal French door in our Steal This Look: Brooklyn Heights Kitchen post a while back that we thought it our civic duty to provide some sourcing ideas. Steel windows and doors have many advantages: due to the material's strength, steel windows have very slender sight lines, they work well in both traditional and modern houses, and they require minimal upkeep compared with wood windows and doors. Here are four suppliers that come highly recommended by several architects and builders we quizzed.

BLISS NOR-AM

This Rochester, NY/Canada-based company makes high-quality, beautifully detailed powder-coated metal doors and windows. To see a gallery of options, visit Bliss Nor-Am.

CRITTALL WINDOWS

This venerable company was founded in 1889 in the UK and has provided windows and doors to Yale University, Walter Gropius, and the New York Botanical Gardens. San Francisco architect Malcolm Davis used them in the project shown below; go to Crittall Windows for information.